You are here:
Structural watershed controls on headwater streamflow permanence: a process-based modeling approach
Citation:
Mahoney, D., J. Christensen, H. Golden, C. Lane, G. Evenson, E. White, K. Fritz, E. DAmico, C. Barton, T. Williamson, AND K. Sena. Structural watershed controls on headwater streamflow permanence: a process-based modeling approach. 2021 AGU Fall Meeting, New Orleans, LA, December 13 - 17, 2021.
Impact/Purpose:
Headwater streams transport materials and energy to downstream waters but how often they flow and what processes control those flows are difficult to characterize. We used a process-based model to estimate the occurrence of stream flows in three headwater catchment in Kentucky using gauge and logger data to calibrate and verify the model results. The model helps us determine what processes are important and different in the three catchments to determining the probability of stream flow.
Description:
Streamflow permanence supports ecosystem functioning and water quality by enabling hydrologic connectivity between headwater systems and downstream water bodies. Characteristics of streamflow permanence are important metrics for assessing the federal protection of headwater systems. Flow permanence – and the associated expansion and contraction of the stream network – in headwaters is controlled by interactions between hydrologic forcings and a watershed’s structure, such as its morphology, predominant soil types, and geologic setting. Due to the lack of widespread monitoring and subsequent process-based model development, our understanding of controls on headwater streamflow permanence remains limited. In this study, we modify and apply a highly resolved process-based hydrologic model (Dynamic TOPMODEL) to investigate the influence of structural watershed characteristics on streamflow permeance. We simulate and analyze several catchments located in the University of Kentucky’s Robinson Forest (US) representing distinct streamflow permanence and structural underpinnings. We use discharge collected at the watershed outlets, flow-state sensor data in ephemeral, intermittent, and perennial reaches, and observed headwater extent collected from field reconnaissance to calibrate and verify our models. We present preliminary results demonstrating how the variability in watershed morphologic configuration impacts patterns of stream expansion and contraction - and the probability of streamflow permanence.
